Article
Mathematics, Applied
J. Petrillo, J. Glimm
Summary: This paper presents an extension to the Kolmogorov-Obukhov refined similarity hypotheses for universal fully-developed turbulence and applies it to a multifractal model. The development is related to the fully-developed turbulence state and describes the coupling between velocity fluctuations and averaged energy dissipation at all orders. The reparametrization of the She-Leveque model is unique and preserves its original forecasts while being infinitely divisible.
PHYSICA D-NONLINEAR PHENOMENA
(2022)
Article
Chemistry, Physical
Guo-qiang Feng, Wen-de Tian
Summary: The desorption of a self-propelling filament from an attractive surface was studied using computer simulations, investigating the effects of activity, chain length, and chain rigidity. Different scaling regimes were observed for the desorption time versus activity for a flexible filament, with varying scaling exponents. The desorption behavior at low activity was found to be influenced by spiral-like detachment kinetics, while at high activity, the desorption process resembled the escape mechanism of a super-diffusive blob from a potential well at a short time scale. The desorption time was also influenced by chain length and chain stiffness, with non-monotonic behaviors observed.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Polymer Science
Antonio Lamura
Summary: The dynamical response of a tethered semiflexible polymer with self-attractive interactions under an external force field was numerically investigated by varying stiffness and self-interaction strength. Different parameters led to various transitions and morphological changes in the polymer chain. The study showed that the external force had significant effects on the conformation and deformation of the polymer chain.
Article
Chemistry, Multidisciplinary
Petra Bacova, Wei Li, Alireza F. Behbahani, Craig Burkhart, Patrycja Polinska, Manolis Doxastakis, Vagelis Harmandaris
Summary: This study investigated the conformational and dynamical features of unentangled and mildly entangled cis-1,4-polybutadiene melts near an amorphous silica surface through atomistic simulations. The results reveal dynamical heterogeneities on the silica surface and suggest that configurational entropy plays an important role in the dynamic response of polymers confined between silica slabs.
Article
Mechanics
Galen W. Ng, Apoorv S. Vishneek, Joaquim R. R. A. Martins, Yin L. Young
Summary: The use of imperfectly scaled models in aerodynamics and hydrodynamics is common due to the difficulty in meeting all requirements. This study aims to derive and validate scaling relations for hydrodynamic composite lifting surfaces, as well as investigate the effects of imperfect scaling. Proper scaling allows for accurate interpretation and assessment of the performance and stability of full-scale flexible composite lifting surfaces.
COMPOSITE STRUCTURES
(2022)
Article
Materials Science, Multidisciplinary
Karin Sim, R. Chitra, Paolo Molignini
Summary: This article employs quench dynamics to study different universality classes of topological phase transitions. The research reveals that the scaling exponent of topological defect density decreases in the presence of nodal loop gap closures. Additionally, a path-dependent crossover between two sets of critical exponents is discovered during a quench through a multicritical point. Bloch state tomography uncovers differences in defect trajectories for sudden quenches. It is found that while Dirac transition allows for a static trajectory under specific initial conditions, the underlying nodal loop leads to complex time-dependent trajectories in general. Notably, a mismatch is observed between the momentum modes where topological defects are generated and where dynamical quantum phase transitions occur in the presence of a nodal loop, although there are exceptions where this correspondence breaks down completely.
Article
Chemistry, Physical
Diego G. Gomez, O. Gonzalez-Amezcua
Summary: In this study, we investigate the equilibrium conformations of a polymer near an attractive surface under different solvent quality and polymer stiffness conditions. Our results show that changes in solvent quality have a greater impact on the conformational variety compared to stiffness, mainly affecting the degree of adsorption. We also find that the adsorption transition is independent of both solvent quality and stiffness. Interestingly, the perpendicular component of the radius of gyration to the surface, R-gx, serves as a consistent indicator for the adsorption transition in all simulations, regardless of solvent and stiffness variations, which may aid in locating this transition in other systems.
MOLECULAR SIMULATION
(2023)
Article
Multidisciplinary Sciences
J. Tomas Lazaro, Tomas Alarcon, Carlos P. Garay, Josep Sardanyes
Summary: Slowing down occurs in dynamical systems close to bifurcations or phase transitions. We numerically investigated the effect of intrinsic noise on the deterministic picture and found a more complicated scaling law. Using a Wentzel-Kramers-Brillouin asymptotic approximation and the Master Equation, we provide a theoretical basis for this new law with two models of cooperation. Our approach allows for useful theoretical predictions of transient times in stochastic systems close to a bifurcation.
PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2023)
Article
Mechanics
Tongwei Zhang, Jie Wu, Xingjian Lin
Summary: This paper investigates the rebound and lateral motion of water droplets on solid surfaces with different wettability. The effects of various parameters on the droplet lateral motion are studied numerically and theoretically. A relationship between the lateral motion and the impact conditions is derived and validated through experimental data. The findings contribute to a better understanding of droplet manipulation and control.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2022)
Article
Multidisciplinary Sciences
Luiz G. A. Alves, Diego Rybski, Haroldo V. Ribeiro
Summary: Urban scaling theory explains the increasing returns to scale of urban wealth indicators based on the per capita increase of human interactions within cities. Incoming commuters' contribution to urban GDP depends on whether the product of population and commuters exceeds a certain threshold for increasing returns to scale.
SCIENTIFIC REPORTS
(2021)
Article
Polymer Science
Emmanuel N. Skountzos, Katerina S. Karadima, Vlasis G. Mavrantzas
Summary: The study investigates the impact of adsorbed domains and nanoparticle bridging chains on the properties of attractive polymer nanocomposite melts through MD simulations. The presence of adsorbed polymer significantly affects the dynamic and conformational properties of the nanocomposite, especially under conditions favoring higher surface-to-volume ratios. Moreover, the bridging chains drive the formation of a nanoparticle network which becomes denser and stronger with increasing concentration of the polymer matrix in nanoparticles.
Article
Astronomy & Astrophysics
Kangjae Lee, Tetsuya Shiromizu, Keisuke Izumi, Hirotaka Yoshino, Yoshimune Tomikawa
Summary: This article reexamines the concept of the attractive gravity probe surface as an indicator for gravity strength, proposing three new variant concepts and providing refined inequalities for the four types of these surfaces, considering angular momentum, gravitational waves, and matter.
Article
Multidisciplinary Sciences
Antonio Curado, Bruno Damasio, Sara Encarnacao, Cristian Candia, Flavio L. Pinheiro
Summary: Public procurement refers to the purchase of services, goods, or works by public sector entities, and this accounts for a significant share of OECD countries' expenditures. The study found that public procurement expenditure scales sublinearly with population size, indicating an economy of scale for public spending with increasing city population. By looking at Scale-Adjusted Indicators by contract categories, a richer local characterization of municipalities based on the similarity of procurement activity can be identified, providing policymakers with a more appropriate foundation for comparative analysis.
Article
Chemistry, Physical
Ganghee Park, Hyangseok Lee, Jae Hyun Sim, Ahyun Kim, Myungwoong Kim, Keewook Paeng
Summary: In this study, an approach to examine local segmental dynamics of a polymer near the interface of an inorganic filler was demonstrated by observing the rotational dynamics of fluorescent probes attached to the ends of polymer brushes. The localization of the probes was achieved by designing and synthesizing fluorophore-tethered polystyrene brushes on the surface of controlled-sized silica particles. By controlling the molecular weight and density of the grafted polymer chains, the observed dynamics were not affected by the polymer brush conformation and brush-matrix polymer entanglement. It was found that the polymer dynamics near the interface in the inorganic/polymer composite geometry remained unchanged when there was no interaction between the surface and the matrix polymer.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Mechanics
Qiang Ma, Yi-Feng Wang, Yi-Bo Wang, Ben-Xi Zhang, Shao-Fei Zheng, Yan-Ru Yang, Duu-Jong Lee, Xiao-Dong Wang
Summary: The effect of surface wettability on the contact time of nanodroplets impacting solid surfaces is investigated using molecular dynamics simulations. The results show that surface wettability has a significant influence on the contact time and restitution coefficient of the nanodroplets, even for superhydrophobic surfaces. The study also establishes theoretical models for the maximum spreading factor, spreading velocity, and retraction velocity, and proposes scaling laws for the spreading and retraction time.
Correction
Chemistry, Physical
Sergey V. Sukhomlinov, Martin H. Mueser
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Chemistry, Physical
Sergey Sukhomlinov, Martin H. Mueser
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Multidisciplinary Sciences
Riad Sahli, Aubin Prot, Anle Wang, Martin H. Mueser, Michal Piovarci, Piotr Didyk, Roland Bennewitz
SCIENTIFIC REPORTS
(2020)
Article
Engineering, Chemical
Anle Wang, Martin H. Mueser
Summary: In this work, the elastic contact between isotropic and anisotropic, rigid, randomly rough surfaces and linearly elastic counterfaces, as well as the subsequent Reynolds flow through the gap between them, is numerically studied. The percolation threshold is found to be dependent on fluid flow direction in anisotropic systems, and a critical contact area near 0.415 is confirmed. Effective-medium treatments provide accurate expressions for Reynolds fluid flow conductances.
Article
Chemistry, Multidisciplinary
Hongyu Gao, James P. Ewen, Remco Hartkamp, Martin H. Mueser, Daniele Dini
Summary: The study investigates the kinetic friction performance of organic friction modifiers (OFMs) at a nanoscale using nonequilibrium molecular dynamics simulations. By studying the coverage of stearamide OFMs, the research reveals that the friction coefficient and indentation depth exhibit nonmonotonic relationships at different coverages.
Article
Engineering, Chemical
Martin H. Mueser
Summary: The study found an approximately linear relationship between the relative contact area ar and pressure p above the critical dimension, and the pressure dependence of the mean gap ug showed identical trends in each studied case.
Editorial Material
Engineering, Chemical
Martin H. Mueser
Article
Engineering, Chemical
Sergey V. Sukhomlinov, Martin H. Mueser
Summary: Through density-functional theory simulations, it was found that initially disconnected zinc phosphate molecules undergo hybridization changes in response to externally imposed deformations, resulting in the formation of rigid networks. Stress anisotropy reduces the pressure required for network formation, while networks formed under isotropic deformations are stiffer, more isotropic, and lower in energy after decompression. Stress-memory effects were found to be encoded in the arrangement of atoms in the second neighbor shell of the zinc atoms.
Article
Materials Science, Multidisciplinary
Hongyu Gao, Tobias P. W. Menzel, Martin H. Mueser, Debashish Mukherji
Summary: In this study, the prediction of specific heat is corrected for quantum effects using an analysis of the mass-weighted velocity autocorrelation function, leading to agreement with experimental data. Corrections for both all-atom and united-atom descriptions of chain molecules are outlined, and deviations between computed corrections and experimental values are found to be small.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Physics, Multidisciplinary
Martin H. Mueser, Bo N. J. Persson
Summary: This article presents simulations on the sticking contact between a rigid cylinder and a viscoelastic half space, revealing a maximum in the work of separation at intermediate pull-off velocities. The maximum tensile forces increase monotonically with the pull-off speed and the crack tip speed, consistent with the Persson-Brener approach. Additionally, the fracture mode transitions from interfacial crack propagation to quasi-uniform bond breaking with an increasing range of adhesion.
Article
Engineering, Chemical
Sergey V. Sukhomlinov, Guido Kickelbick, Martin H. Mueser
Summary: Using molecular dynamics simulations based on density-functional theory, this study investigates stress and temperature-induced chemical reactions in systems containing triphosphoric acid and zinc phosphate molecules. The findings reveal that the nature of the products depends on the applied conditions, with isotropic and shear stress leading to different (zwitter-) ionic products. Thermal cycles also generate free ions, but these reactions are endothermic instead of exothermic like stress-induced transitions. The study also shows that before zinc atoms change their coordination under stress, proton mobility increases, and the hydrostatic stress required for this process is reduced with increasing shear. These findings have implications for understanding the impact of stress on material properties.
Article
Materials Science, Multidisciplinary
Christian Mueller, Manar Samri, Rene Hensel, Eduard Arzt, Martin H. Mueser
Summary: Viscoelasticity and small-scale, elastic multistability are two mechanisms that contribute to adhesion hysteresis. This study compares the simulated and experimental results of the interfacial force and contact area evolution between a soft elastomer and a rigid punch with roughness. The findings reveal that hysteresis is enhanced when the topography's saddle points come into contact, but is impeded by viscoelastic forces and may require large preloads. This coaction of viscous and multistability effects is relevant to macroscopic polymer contacts and adhesive gripping devices.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Physics, Multidisciplinary
Christian Mueller, Martin H. Mueser, Giuseppe Carbone, Nicola Menga
Summary: This study investigates the impact of the coupling of normal and in-plane elastic response on the tribological properties when Hertzian or randomly rough indenters slide past an elastic body. The study finds that compressibility-induced coupling increases maximum tensile stresses and decreases friction, violating Amontons' law macroscopically.
PHYSICAL REVIEW LETTERS
(2023)
Article
Engineering, Mechanical
Anle Wang, Yunong Zhou, Martin H. Mueser
Summary: This study quantitatively analyzes the energy loss phenomenon during contact between rigid indenters and adhesive surfaces, with a focus on the design of cohesive-zone models for efficient simulation of dynamic processes.
Article
Engineering, Mechanical
Martin H. Mueser
